Colombo, Sri Lanka (CNN) -- A Saudi employer and his wife, who are accused of torturing a Sri Lankan housemaid by hammering nails into her body, have been arrested in Riyadh, Saudi Arabia, officials at the Sri Lankan External Affairs Ministry said Monday.

Saudi Arabian authorities could not be reached immediately for verification. No further details were available.

The two suspects have not been named.

Doctors at a Sri Lankan hospital operated for three hours Friday to remove 18 nails and metal particles allegedly hammered into the arms, legs and forehead of a maid by her Saudi employer.

Dr. Kamal Weeratunga said the surgical team in the southern town of Kamburupitiya pulled nails ranging from about 1 to 3 inches from Lahadapurage Daneris Ariyawathie's body. He said doctors have not yet removed four small metal particles embedded in her muscles.

"She is under heavy antibiotics but in a stable condition," Weeratunga said.

Sri Lankan officials, meanwhile, met with Saudi diplomats in Colombo to urge an investigation into the incident.

"It was cruel treatment, which should be roundly condemned," said L.K. Ruhunuge of the Sri Lanka Bureau of Foreign Employment.

He said the Sri Lanka government has forwarded to Saudi authorities a detailed report on the incident, including statements from Ariyawathie.

Ariyawathie left Sri Lanka on March 25 to work as a housemaid in Riyadh after the bureau registered her as a person obtaining a job from an officially recognized job agency.

She was held down by her employer's wife while the employer hammered the heated nails, Ruhunuge told CNN. She apparently had complained to the couple that she was being overworked, Ruhunuge said.

The nails were hammered into her arms and legs while one was on her forehead, he said.

"Most of the wounds are superficial but five to 10 are somewhat deep," said Dr. Prabath Gajadeera of the Base Hospital. "Luckily, none of the organs is affected. Only nerves and blood vessels are affected."

Ariyawathie, 49, is a mother of two children who were opposed to their mother's journey to Saudi Arabia for work.

Several countries across the Middle East and Asia host significant numbers of migrant domestic workers, ranging from 196,000 in Singapore to about 1.5 million in Saudi Arabia, according to a report published earlier this year by Human Rights Watch.

Many of the domestic workers are poor Asian women from Sri Lanka, Indonesia, India, Bangladesh, the Philippines and Nepal. Widespread abuse has been documented by global human rights groups.

Common complaints include unpaid wages, long working hours with no time for rest and heavy debt burdens from exorbitant recruitment fees, said the Human Rights Watch report.

Isolation and forced confinement contribute to psychological and physical abuse, sexual violence, forced labor, and trafficking, the report said. The abuse often goes unchecked because of a lack of government regulation and protective laws.

Ruhunuge said the registration of the local job agency that placed Ariyawathie has been cancelled.

"We have also asked [them] to pay compensation to the victim," he added. "We want to bring those responsible for justice. We are doing our best in this regard," he said.

He said his office was ready to accompany Ariyawathie to Saudi Arabia to testify if a case is brought against her former employers.

Ariyawathie's dream was to one day return to Sri Lanka and build a house with the money she saved.

"We are looking at the possibility of helping her to do this," Ruhunuge said.

Karu Jayasuriya, deputy leader of the main opposition United National Party, visited Ariyawathie in the hospital and said he was appalled.

"We want the government to raise this issue at the highest levels with the Saudi government. We cannot imagine that such crude and uncivilized things are happening to our workers," he said.